Hyvää Uuttavuotta!

Hyvää uuttavuotta kaikki! Minä kävin eilen tyttöystäväni luona. (Minä) Pidin siellä hauskaa. Näin ilotulituksen ja puhuin monille ihmisille joita en ollut ennen tavannut. Se oli tosi juhla.


You didn't screw it up too bad. Your second sentence in its original state would've meant (ignoring the mistakes) "I came to visit my girlfriend yesterday" so I changed it to " I visited my girlfriend yesterday". Nouns and verbs both conjugate depending on the personal pronoun so technically both of the Minäs are a bit redundant. As for the word order, I think Finnish is quite flexible and your original "Minä pidin hauskaa siellä." would be understood, but it sounds more natural like this.

I thought about 'tosi juhla' for a while. It should probably be 'todellinen juhla' as 'tosi' usually means 'true' as in true story, but it can also be used kind of like 'killer party' so I think it's fine.